What happened
Following touchdown, a vibration occurred within the landing gear assembly. At a speed of 117 knots, this vibration resulted in the collapse of the right main landing gear. As the gear failed, the right wing made contact with the runway, and the aircraft skidded along the runway surface until it came to a stop as it entered the overrun area.
During the subsequent emergency evacuation, two passengers sustained minor injuries.
The investigation
An examination of the relevant components was conducted, though investigators could not identify a specific cause for the initial vibration that triggered the collapse. However, the inspection revealed that the threads on the right gear apex bolt failed, which caused the landing gear to rotate 90 degrees and led to the subsequent overload collapse.
Investigators also noted that the ground spoilers did not activate during the event. Although the crew reported that they had armed the auto spoilers, the system failed to deploy. The manufacturer indicated that this was one of three similar non-flight test occurrences where the ground spoilers failed to extend.